Ornamental design for a tricycle



FIG. 1 is a right side perspective view of a tricycle showing my newdesign.

FIG. 2 is a left side elevational view thereof.

FIG. 3 is a top plan view thereof.

FIG. 4 is a front elevational view thereof.

FIG. 5 is a rear elevational view thereof.

The ornamental design for a tricycle, as shown.